Dometic fridge auto selections - Page 2

Mike · 06-12-2013, 07:01 PM

We don't use our fridge in the traditional sense, to keep larger quantities of food from spoiling while traveling from place to place. While on the road we usually just keep bottled water, pop, or beer cold in it, or maybe to keep some leftover salads/pastries cool, and we run it on DC while driving to do so (as most probably do). I have forgotten to switch it off DC at the fridge control panel, after stopping for the night, and have wondered why the batteries are so low when I get up in the middle of the night (force of habit to check the systems status at the monitor panel when nearby). It's a (dim

) light bulb moment, usually.

Davydd · 06-12-2013, 07:02 PM

Here is the 2005 Pleasure-Way Plateau battery disconnect switch located in a cabinet under the sofa bed ottoman in the back of the van.

Here is a new Great West Van Legend battery disconnect switch located under the kitchen cabinet with the sliding door open.

Davydd · 06-12-2013, 07:11 PM

Quote:

Originally Posted by Mike

We don't use our fridge in the traditional sense, to keep larger quantities of food from spoiling while traveling from place to place. While on the road we usually just keep bottled water, pop, or beer cold in it, or maybe to keep some leftover salads/pastries cool, and we run it on DC while driving to do so (as most probably do). I have forgotten to switch it off DC at the fridge control panel, after stopping for the night, and have wondered why the batteries are so low when I get up in the middle of the night (force of habit to check the systems status at the monitor panel when nearby). It's a (dim

) light bulb moment, usually.

Thus why the automated 3-way instead of manual Dometic and back to topic.

We have a routine and primary responsibilities for stopping and getting underway, and we check each other for redundancy after we've done them. We also hang reminder "bees" (little stuffed toy bees) on things that have to be attended to such as lowering the TV antenna. After we pull out of a site, we do a visual inspection of the campsite to make sure nothing has been left behind. We haven't gone so far as checking off a list like I know some people do.

Mike · 06-12-2013, 11:24 PM

I don't have to walk as far to get to my battery disconnect switch, as I do to my fridge control dials. It's a full step farther down the main aisle to the fridge, than it is to the monitor panel. That's why I use it.

re: those battery disconnect locations. ugly. ours is actually a disable which probably uses an electric switch or solenoid/relay of some sort, not a physical disconnect like the ones in the picture. I can hear the solenoid/relay engage and disengage when I use ours. Yours look like the 300A-500A models you can buy at Advanced Auto, AutoZone, etc., and are heavy duty physical cable disconnects, capable of handling the arcing that occurs when those types of switches are used. They're probably a pita to replace, too.

re: back to topic. Use DC while driving to run your fridges, and leave the auto AC/Propane power source selection switch disabled, if possible. If that doesn't work, buy a big bag of ice, split it up and place it inside your fridge/freezer, and don't use power with your fridge while driving.

Davydd · 06-12-2013, 11:39 PM

So, you are saying you prefer to shut down your whole B, including detectors, alarms, lighting, outlets, heater, etc. just to turn off DC on your refrigerator?

mlts22 · 06-12-2013, 11:43 PM

Maybe a compromise would be having a disconnect switch just for the refrigerator? Perhaps a DPST or DPDT type of switch so 120 volts and 12 volts can be disconnected at the same time, or if one is sure that it won't get 120VAC unless on generator or shore power, a regular battery disconnect switch can do.

booster · 06-12-2013, 11:47 PM

Quote:

Originally Posted by Davydd

So, you are saying you prefer to shut down your whole B, including detectors, alarms, lighting, outlets, heater, etc. just to turn off DC on your refrigerator?

That is what this is all about, if you just shut off the DC on the frig, it switches to AC or propane and will try to light. To be safe you have to use the on/off button. But, as folks have said, you still have a water heater that may try to light if it is on but not totally hot. Turning off the entire coach (there is no penalty that I know of) is very easy in our Roadtrek, and is as foolproof as you can get.

Mike · 06-13-2013, 12:07 AM

To keep from exploding at the gas/diesel/propane filling stations?
Yes. I think it's a small sacrifice to pay for your family's safety. Particularly if you have an automatic AC/Propane selector that might fire up the propane, or accidentally fire up the furnace or water heater.

Some may prefer to rationalize the other options for shutting off any flame/spark related systems, but I'd rather not end up like the couple at this filling station who spilled a few drops of gasoline into the back of the fridge area, while the propane was on, and burned their rig to the ground. It's not exactly the scenario this thread was started about. Or, was it?
http://www.houmatoday.com/article/20...CLES/100329598
While this sort of thing might be rare, it does and can happen to anyone.

Davydd · 06-13-2013, 12:16 AM

Just turn the whole refrigerator off. I can do that with my 3-way. Push and hold the button 2 seconds until the idiot lights go out. Even if a refrigerator is an automated one you still have to be able to shut it off without shutting down the B. Unless your disconnect switch is easily accessible while sitting in the driver's seat then shutting down the whole B makes little sense to me because you have to get up and walk back into the coach anyway.

teachergal · 06-13-2013, 01:01 AM

On my PW van I have propane switch - it's on the outside of the coach in the compartment with the electrical plug & cable hook up - when I'm planning on getting fuel I switch the fridge to DC and jump out and shut off the propane. That way none of the propane appliances can or will ignite. I try to do this at the last stop before refueling or when I set out in the morning for a day long drive.

I have put the fridge on DC to drive and forgotten and stopped for over an hour and yes, it killed my battery and I didn't realize it until the next day b/c I didn't drive enough after to fully charge it, but it appeared charged.

I do not keep my fridge on auto. ever. One time I was dry camping and I had the propane fail to ignite in the middle of the night. Since the fridge was set to LP it alarmed when it couldn't ignite. Yes, it woke me up, but I was glad it didn't automatically switch over to DC and drain the battery. I never would have noticed that the fridge was running on DC until battery was dead - and even then it probably wouldn't have occurred to me that the fridge was the culprit.

Mike · 06-13-2013, 01:41 AM

Quote:

Originally Posted by teachergal

On my PW van I have propane switch - it's on the outside of the coach in the compartment with the electrical plug & cable hook up - when I'm planning on getting fuel I switch the fridge to DC and jump out and shut off the propane. That way none of the propane appliances can or will ignite. I try to do this at the last stop before refueling or when I set out in the morning for a day long drive.

I have put the fridge on DC to drive and forgotten and stopped for over an hour and yes, it killed my battery and I didn't realize it until the next day b/c I didn't drive enough after to fully charge it, but it appeared charged.

I do not keep my fridge on auto. ever. One time I was dry camping and I had the propane fail to ignite in the middle of the night. Since the fridge was set to LP it alarmed when it couldn't ignite. Yes, it woke me up, but I was glad it didn't automatically switch over to DC and drain the battery. I never would have noticed that the fridge was running on DC until battery was dead - and even then it probably wouldn't have occurred to me that the fridge was the culprit.

That covers it pretty well, too, stopping the propane at the source. My concern would be that with the DC battery power still available, any DSI igniter on any propane appliance (furnace, fridge, water heater) might still fire a couple of times before it triggers the "failed to light" alarm, which might be problematic, if it tried while you were refueling.
I think that is what this thread's OP was concerned about, when switching the automatic fridge off it's DC setting. Would it try to switch to AC first, and not finding any, then ignite the propane burner? If you disabled the coach batteries, the fridge wouldn't be able to fire up the propane, even if it was on automatic power selection mode with no AC available. No DC either, probably means no DSI ignition.

It is easy to forget to turn the fridge OFF of DC when you stop. Been there, dumbed that.

Rok · 06-13-2013, 04:43 AM

Some of us don't have a propane water heater. Our 2013 GW Legend SE for instance has a diesel hydronics system. When we pull in for fuel, we have the refrigerator on 12V DC, and because our unit won't auto select DC (it has to be manually chosen), it won't switch to propane (at least I don't think it will). Even if it did, we keep the propane spigot "off", so the propane wouldn't light. Yes, if it did switch over because the battery was low or some such, it might spark, trying to ignite the propane, but I doubt that spark would be a REAL hazard while pumping fuel. Yes there is a one in million (or more like one in a billion) chance that it might, but I'll take those chances. I think the chances of me forgetting to turn the main power back on and getting asphyxiated while I sleep are higher.

There is a point where our fears and concerns become unreasonable and we are taking REAL time and REAL energy to prepare for imaginary risks.

Aren't you (meaning "isn't one") supposed to turn off the propane while traveling so there would be less chance of problems? I think our manual says that. We are also not supposed to be running around with the diesel hydronics on, either. We do have propane for the generator, stove, and refrigerator and we turn the crank on the bottle when we start to move.

Please correct me if I'm wrong, but I think what we do is appropriate. We leave the refrigerator on 12V DC while fueling with diesel (with the diesel hydronics OFF and the propane tank OFF).

........Rocky

Mike · 06-13-2013, 01:45 PM

One thing that is certain, is that everyone has their own opinion of how to deal with the various safety issues that arise when traveling by RV. I've discovered this over 5 years of traveling, and by following similar discussions to this one, on more than one forum. I always try to caveat what I type with "in my opinion" whenever it's just that. Most of my posts are opinions, except in rare cases where I may post a link to data that supports them, or simply because someone is looking for a source of data for reference.

So, the best answer (again, in my opinion) for dealing with appliance statuses while refueling, is probably to do whatever the owner's manual tells you to do, in compliance with local, State, and Federal laws governing the specific situation. Using the example of refueling, there are at least 5 specific laws posted at every pump regarding things like re-entering your vehicle, use of electronic devices like cell phones, smoking, and which includes turning off or extinguishing all sources of ignition. Even with these refueling laws posted at the pumps, I have heard over and again from many RVers on different forums that they are "overkill", and so they often neglect or refuse to follow them. It has reached a point with me where, if I see another RV refueling at a place we've stopped, I'll sit and wait until they move away from the pumps, because I can't be sure whether or not they have their own book of "safety rules".
If you need clarification about the safe function of any of your RV systems, consult the RV manufacturer. If the manufacturer is no longer available, consult the individual appliance manufacturer. They have in all likelihood been subjected to significant UL/CSA/TSSA etc. standards testing, to prove that their devices won't hurt or kill their owners when used in accordance with their installation and operational instructions.

Regarding correcting you if you're wrong. I can't, because I'm not familiar with your unit, so I don't understand the ramifications of the specifics of what you're doing. In a general sense, I can suggest what I think are appropriate safety precautions, based on my knowledge and experience, and that's about it.
AFAIK, you have a unit with which Davydd is probably most familiar, so if you're looking for an opinion or advice on best practices, his would be based on the most practical experience with a similar unit.

Davydd · 06-13-2013, 02:06 PM

I had the propane shutoff switch on my 2005 P-W Plateau. I never understood how a toggle switch could close a gas valve. Can anyone explain that? Is it not doing that and just stopping electrical ignition? Some ferries, most recently the ferry on Galveston Island, make you visually show them the propane valve is shutoff. On my Pleasure-way the valve is located at the tank on the passenger side right under the sliding door entrance. There is a lift door to expose it but you can easily reach under and shut it off by turning the valve handle without lifting the door. This is the view of the yellow fill valve, the shutoff valve, the BBQ connection and the regulator on the Great West Van Legend.

markopolo · 06-13-2013, 02:44 PM

The propane switch would most likely activate a solenoid to shut off the propane. It could be located after the regulator but it would stop the flow of propane gas to the appliances.

I like the idea of using the battery disconnect switch when refueling. It had never occurred to me to use it that way but it would eliminate any 12v ignition sparks - water heater, furnace, hydronic heating, fridge etc. As noted though you'd have to remember to turn it back on.

When your are in the coach, keeping the battery disconnect on will keep your C0 and Propane detectors working so I think that is a good idea.

Mikes link: http://www.houmatoday.com/article/20...CLES/100329598 reported that the problem was caused by gas "spewing" from the pump nozzle into the fridge vent ! ! !

This is a good topic. Everyone will decide what is appropriate for them and their RV and it presents ideas that may not have been considered previously.

Shutting off the manual valve on the propane tank before driving is the safest way. I don't do that but think I should start. It doesn't take much effort to do it. I'd need a reminder to "turn on propane" posted near the fridge until it becomes ingrained.

As Rocky pointed out we can over think this stuff so I guess it is just a matter of knowledge of the risks great and small and then deciding what works for you.

booster · 06-13-2013, 09:57 PM

I agree with Marko, this is a very useful topic. We don't have a propane frig, and rarely use the water heater or stove, so our propane is off nearly all the time. We turn it on to use the grill or water heater as needed and then turn it off. Of course that doesn't eliminate the water heater trying to light if someone accidentally bumped the switch for it.

We hadn't been shutting off the 12v power switch that is on the monitor panel when we get gas, but it is so easy, and so foolproof, we will start doing it. Why try to remember to check all the other stuff, when you can flip one switch and be at 100%.

Davydd · 06-13-2013, 11:07 PM

Quote:

Originally Posted by markopolo

The propane switch would most likely activate a solenoid to shut off the propane. It could be located after the regulator but it would stop the flow of propane gas to the appliances.

Does a solenoid via a toggle switch do this?

http://www.youtube.com/watch?v=X2nro3lfaqw

Davydd · 06-13-2013, 11:21 PM

This is all getting confusing. We pull up to a service station and worry about propane being on or off. Propane does not ignite gasoline or diesel fuel. Electrical ignition does that. So to be safe couldn't you leave propane on but be required to shut down your electrical systems? Given that, wouldn't it be just as dangerous to start a car at a service station? It is beginning to sound if everyone has it backwards.

It seems the danger lies with a faulty propane system which could rear its ugly head at anytime or in the case of an accident. The accident factor would dictate prudence in turning off the propane at the tank.

markopolo · 06-14-2013, 12:34 AM

re: the solenoid - yes that is my basic understanding of how it works. Physically shutting off the propane for travel is a good idea in case of an accident. Having it shut off in case of fire at the pumps would at least keep it from feeding the fire.

These types of fires are probably very rare events.

Mike · 06-14-2013, 05:22 AM

re: confusion....
Gasoline or any other low ignition point flammable material (paint thinner, rubbing alcohol, etc.) can be caused to burn by two methods that are available on the average RV incorporated into more than one on board system.
A spark igniter, either manual (a push button on my old Dometic fridge as an example) or a DSI (Direct Spark Ignition) igniter which is normally powered by the RV 12V DC coach battery power when you select DC Power (an engine spark plug is similar to a DSI igniter). These types of igniters are found in absorption fridges, furnaces, and water heaters. My Roadtrek has all three systems, my fridge uses a manual push button spark ignition system, and the other 2 use DSI ignition. YMMV.
The other thing that can ignite flammables, like gasoline, is an open flame (a pilot or burner). A water heater has an open flame/burner jet after it fires up, as does a furnace, and an absorption fridge has a pilot type flame when running on propane. It was the fridge's open flame that resulted in that couple's van burning at the pumps when they spilled gas into the fridge vent onto it.

Having said that, and assuming your fridge is running on DC while you're driving, and you stop for gas, if you disable the coach batter(y)ies, you've disabled the chance of an automatic DSI igniter creating a spark that could ignite gasoline or other flammables. in the unlikely event one of your other propane based systems is running on propane while you're driving, you should also shut it off. You probably don't need to shut off the propane at the tank while driving, but it is recommended by many RV manufacturers, in the event that there's an accident, and the propane appliances and conduit lines are damaged.
Agree with booster (which is why we've done it for years) - it's as close to 100% as you can get with one switch. As I also said farther back, maybe some newer class B vans don't have battery disable switches that are placed conveniently, or at all. Davydd's 2 units appear to have much larger coach battery disconnects, not disable switches like booster and I have in our Roadtreks, so it may be harder to do on a PW or GWV at each stop.
What do others have in their vans? Physical cable disconnect, or rocker switch and solenoid/relay disable?

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